Air Escaping From Fuel Cap

[TonyAYGO]

This is my first car so im not sure whether this is normal, but when I go to fill up with petrol, and unscrew the petrol cap, a lot of air escapes when I take it off. Quite a lot really, it sounds as if is a vaccum or something in there lol.

Why is this?

thanks

[FunkyDonkey]

This is quite normal, and happens on lots of cars. It is because of a vacuum being created in the fuel tank, which is then removed when you remove your fuel cap.

[TonyAYGO]

This is quite normal, and happens on lots of cars. It is because of a vacuum being created in the fuel tank, which is then removed when you remove your fuel cap.

oh okay thats good then

Thanks :)